I have 4 cats that get washed on a regular basis (once every 3 months) because 3 of them are therapy cats that go to visit sick kids at the Children's Hospital, so they need to be clean.
I trim their nails 2 days prior to bathtime. I have one of those anti-slip mats that I put in the bath tub, and I have a hand-held shower attachment in the tub/shower. I just gather them up, one at a time and wash them with the hand-held shower attachment. I use very mild no-tears cat shampoo that even smells wonderful. My cats are very used to being washed, and although they're not crazy about it, they don't fight or scratch when they're being washed.
I towel them dry, and them I keep my house warm, since they do not like the blow dryer.